This invention relates to programmable motors and, more particularly, to a motor having a plug-in programmable module and which motor operates in response to information provided by the plug in module.
Many systems include motors which drive a fluid in a system. For example, in heating, ventilating and/or conditioning (HVAC) systems, a motor is used to drive a fan which effects air movement. Depending on the particular environment in which the system is installed, the system and the motor, in particular, must operate according to various parameters and according to various cycles or sequences.
Present motors have a variety of features and operational and system parameters which must be adjusted to optimize performance by providing a proper speed-torque characteristic for a particular application. Further, in many system applications, the starting torque and/or speed torque characteristics of the motor must be predictable and repeatable. In addition, it is desirable that motors be operable at highest reasonably achievable efficiency consistent with mass production techniques. Present concepts and arrangements for adjusting a motor for different field applications require circuit changes such as multiple variable resistors in the electronic control for the motor or permanent software changes in an electronic controlled microprocessor.
Both of the aforementioned arrangements are disadvantageous because they require a unique model to be built for calibrating a system which cannot be easily changed in the field and can be quite expensive.
More recently, a control system and method for a multi-parameter electronically commutated motor has been developed such as disclosed in U.S. Pat. No. 5,592,058, co-assigned to General Electric Company, the entire disclosure of which is incorporated herein by reference. In this system, it is contemplated that the motor drives a component in response to a control signal generated by a microprocessor. The microprocessor is responsive to parameters representative of the system and to a system control signal. The parameters are stored in a memory and are defined in response to a parameter select signal. The control signal provided by the microprocessor controls the speed and torque of the motor. The system further includes an instruction memory for storing instructions controlling the operation of the microprocessor.
Another approach is disclosed in Canadian Patent No. 2,148,633. A drive apparatus for use with a dynamoelectric machine includes a drive means connected to the dynamoelectric machine to control at least one of the current or voltage of the machine. Processing means supplies machine control information to the drive means and includes a first memory means, a program means in the first memory means, a second memory means, and operating characteristic information in either memory means. A switch means connected to the processing means has settings which select operational characteristic information from either memory means.
While present motors have some programmable features, there is a need for a field programmable motor with even greater programming flexibility.
In an exemplary embodiment of the invention, a motor for use with a power supply comprises a rotor, a stator, a power switching circuit, a microprocessor circuit, a housing, a module and a module connector. The stator is coupled to the rotor and has windings for generating a magnetic field applied to the rotor for rotating the rotor relative to the stator. The power switching circuit is connected between the windings and the power supply for selectively energizing the windings to generate the magnetic field applied to the rotor to cause the rotor to rotate. The microprocessor circuit includes a microprocessor controlling the power switching circuit. The housing encloses the rotor, the stator, the power switching circuit and the microprocessor circuit. The module has a module circuit for controlling the operation of the microprocessor circuit. The module connector is within the hosing, accessible through an opening in the housing, connected to the microprocessor circuit and releasably receives the module. The module connector receives the module and connects the module circuit to the microprocessor circuit. The microprocessor circuit is responsive to the module circuit for controlling the power switching circuit as a function of the module circuit, whereby the operation of the motor is a function of the module circuit.
This motor of the invention has a number of advantages over the prior art. Both the microprocessor circuit and the module circuit are programmable. The modules can be selected in the field and installed to control the operation of the motor. The module can be in the form of a printed circuit board which is low in cost to manufacture and may include either a programmable memory or an executable memory or both mounted on the printed circuit board. Switches may be mounted on the printed circuit board to further permit field programmability and selection of the parameters or executable code which control motor operation. The size of inventory needed to support systems is significantly reduced because one motor with several modules can replace the need for an inventory of several motors. The programmability of the microprocessor circuit and the module circuit permit either or both to be reprogrammed in the field.
Other objects and features will be in part apparent and in part pointed out hereinafter.